Editing Soft tissue sarcoma (section)

=== '''Breast sarcoma''' ===

** Most common - angiosarcoma and phyllodes
** '''Primary angiosarcoma'''
*** Arises in young women
*** Rare vascular tumour (1% of all breast tumours)
*** Forms an ill-defined parenchymal mass
*** Responsive to chemotherapy, but tends to recur once chemotherapy stopped
*** Should have mastectomy as opposed to lumpectomy, and partial pec major resection may be necessary to achieve margins
*** Needs staging with CT CAP and breast MRI
*** No proven benefit from contralateral prophylactic mastectomy
** Secondary angiosarcoma
*** Affects older women, a/w either lymphoedema or breast RTX
*** Cutaneous malignancy as opposed to primary breast angiosarcoma which is parenchymal
*** Purplish vascular proliferation in the irradiated skin
*** Can develop in the ipsilateral arm to surgery - Stewart-Treves syndrome, secondary to chronic lymphoedema (can also be atypical vascular proliferation)
*** If no metastases, needs complete R0 excision (usually mastectomy + resection of all the breast skin)
*** Axillary dissection not required, lymph node metastases are extraordinarily rare
*** Will need extensive reconstruction
*** Adjuvant chemotherapy generally recommended
** '''Phyllodes tumour'''
*** Epidemiology/risk factors
**** Uncommon fibroepithelial tumour
**** Median age 45yo
**** Li-Fraumeni
**** BRCA
*** Pathophysiology
**** Stromal atypia/dysplasia, made up of mixed connective tissue and epithelium
**** Leaf-like papillary projections seen on histopathology
**** Malignant features (two S, two M):
***** Higher degree of stromal cellular atypia
***** Mitotic activity per 10 high powered fields: borderline 4-9, malignant >9
***** Infiltrative margins
***** Presence of stromal overgrowth (i.e. pure stroma devoid of epithelium) - this is the most important feature
**** Metastasises via haematogenous spread - lung, bone, abdominal viscera, mediastinum
**** Recurrence mostly within 2 years
*** Presentation:
**** Clinically firm lobulated mass, average size 5cm, similar to fibroadenoma. Suspect phyllodes with more rapid growth, older patient, and larger size.
**** Mammography - round density with smooth borders, indistinguishable from fibroadenomas
**** USS - discrete structure with cystic spaces
**** CNB is useful, but difficult to accurately assess malignant potential
*** Classification/management:
**** Needs surgery to truly classify, with negative margins
***** Benign phyllodes tumour - 'clear margin' is adequate
***** Borderline/intermediate tumour: excision with negative margins (often suggested to be 1cm margins). 
***** Malignant:
****** Complete surgical excision with a margin of normal tissue - can be WLE or mastectomy
****** Radiation indicated with fascia/chest wall involvement, >5cm size, or only WLE performed.
**** Lymph node biopsy not necessary
**** Systemic therapy has very limited success.
**** Contralateral prophylactic mastectomy not indicated